Grate bar



Jan. 12, 1932. THACHER' J 1,841,307

GRATE BAR Filed June 22, 1927 are not tilted upwardly into the 'fuel' bed as the grate bars of Fig. 1*;and

"35 upwardlythrough the grate. 1

spaced relation to the bar so that the cooling said application;

GEORGE E. Tami-transit; or ME'tnosE, ivmssacnusur'rs IG ATEB BQ 7' I 7 i ap ncauee eled J me. ea, 1927;? serial m5, 255, 7 I

This invention relates to grate bars and Anothenimportant feature of the-present more particularly tothe novel construction invention,resides infithe construction of-the" of the grate b'locks mounted uponithe bars. hollow. grate-blocks whereby all walls and f The stoker bars or grate bars'of the present partitionsjof ablock have substantially the invention are designed more partieularlyfor same thicknessfand the'entireblookconstrue i use me mechanical stockersuchias shown and *tionis. suchaumtalr of. thewwalls and 'par'tidescribedin my co-pending application Ser. tions wi'll'fhe'at up and'cool'oif at about the V i No. 165,088, filed February 1 11927; and:are same rate, to thereby-ireliev'e the block strue particularly well adapted to withstand the turQfi-oiif injurious internalstress'es. *1 i j V *OtherfeQtureS of theinvention and novel: 60 a jctd! 1 V. I a on Of paits'inaddition to the'abov'e Grate or stoker bars asusual'ly constructed will behereinafter described in {connection In high teinperature'sjito which they may be'subheretofore have been of the rockingtype-with the accompanyingdf wing whi h m e; r

which are open to theobjection that when the. trjatelone? good ractica1 orm;- of the in'vena 1.) bars arero'ckedor tilted to shake thefuel bed, tion." r .15 i

the'projection'sor'fingersupon'the gra'tebars 'Inthedrawings .1 i a s that are forced upwardly into thefuel .bed 1 "Figs-lisfla perspectiveviewof ai'portiorr V are subjected t'oan' intense heat that tends-t0 of the gratejshowingthe-composite gratebars destroythe'ni. V F intheir-operative positionj: a V f V H The grate bars' of the present invention are 1g. 2"isia transvers'e s'ectional View t k j supported for sliding movement towards and on the line 2+2 of Fig.4; [11 y 1 from the fuel bed in a direction at substan- V Fig. 3 is atransversesectionalViewthrough tial rightangles tothe planeof the fue'l bed', a supporting bar,"the'blocksbeing-removed; i .e and as a result the edges ofthe grate bars a Fig. is an enlarged side-view. of one'off" in the rocking type of grate. This feature Fig. ]5 is lon itudinal' siectional iview 5 alone materially reducesthe -destructive 'acthrough agrate blocilnmtionof the heat of the fuel bedupon the grate The grate or stoker barskforming the u s. I 1 l v ject matter of'thepres entinvention"are pref:

The upwardsliding movement imparted to erably supported side by side transverselyso thepresent grate bars-hasa further advan vof the furnace, asshownin Fig. 1',; and? are tage in that it permitsa construction whereby mounted for sliding movement towardand i p the grate bars may bev cooled much more eff' fromithefuel bed at a slightinclinationto a fectively thanheretofore byftheair passing vertical' planehas clearly setforthinmy co -1. J

e i j i p'ending'application above inentioned." Ceri Am important featureofthe inventionre tain features in the construction; of thecoma sides ina bar having a series of grateblocks posite'stokerfbars of the present invention 7 mounted thereupon and provided with downmay however-beemployedin;other grate con; y wardly extending side walls disposed in structions than that shownanddes cribed'in currents of airmay pass "upwardly at each Each grate or stokerbar is shown as-con-T side of'the bar between thesi'oles of the bar sistingfofla barLlOfupon which 'areinountedand thespaced sidewalls ofthe blocks mount a s'er'ies of grate blocks. 11 The blocks are preferably six-sided, thatlis, each block has ed thereupon. Y

A further feature of the invention resides aboX-lik'e construction and 'is formed with in the construction ofthe grate blocks 'wherea fiat top and? approximately"parallel side by'the surfaces thereof; that come in'contact and end walls, and the opposite 'side walls;

v with the fuel bed are free fromrexposedipro-e have smooth fiat surfaces thatare free from V r jections that will be burnt 0E by the heat 'of projections and depressions. The blocksare the fuel; showninthedrawings asresemblinga cube width.

.or hexahedron in shape; though if desired ing surface of the blocks, and between the webs 14 are formed the air passages 15. The

end walls 13 and the. central web 14- may extend downwardly asufiicient distance to rest upon the supporting bar- 1O as will be apparent fromFig. ,5 while the webs 14- at each side of-thecentral wall preferably extend downwardly a less distance to facilitate the passage of air into the different passages 10.

In the operationof furnaces and more par= ticul'arly in the operation of heavy duty commercial furnaces where the :grates are subjected to excessively high temperatures,

it is of the utmost importance that-the grate blocks be soconstructed thatfthey .Inay expand and contract freely with changes in temperatures without subjecting any: portion of=the-=blockito pronounced internal-stresses that are-likely,to-;crack-the block. It-is also extremely important that the grate blocks be; so constructed that they afford a maximum amount of radiating surface which is exposedrt o the coolingncurrents of air passing upwardly throughithegrate. v l

The grateblocksofthe present invention fulfill these requirementsremarkably well, and 33403; result they are peculiarly well adapted for use in heavy duty commercial furnaces where they. are subjected to extremely high temperatures. It should be 'noted tlratiall w-allsand partitions or webs of the' presentiblocks' are of practically the same thickness, and 'th at the: air passage bev' tween-any two walls of the assembled blocks from injurious internal stresses.

has approximately the samewidth asthe air passagebe'tween any other two walls, with the 're sultthat all walls and partitions of a block will: heat up and cooloff atabout the same rate,- this relieving the block structure 7 Furthermore, since the walls and partitions are disposed in approximatelyparallel relation and extend downwardly a substantial distance from. the upper face ofthe bloclnleach wall and ,partition has a large radiating surface which is practically equal to the radiating surf-ace of. any other wall or partition of the block. 7 y I These features are believedto bebroadly new, and it is found iupractice that furnaces are made hollow as shown so grate block (2) Equal radiation for all portions of the block and (8) A large percentage of radiating surface as compared with the metal surface exposed to the fire.

The bloc'ks'll' are secured to the bar 10 in the construction shown by extending'the'side portions of the central web-la downwardly to form the fingers 16 that straddle-the bar 10,. and thesefingers arereceived in grooves or slots 17 formed between the spaced projections 18 upon the bar 10. Asa result-of this construction the-blocks 11 are secured to the bar 10 in spaced relation to each other as shown, while at the same time they are free to. expand lengthwise-of thebar in op posite directions from their securing means. The blocks 11 maybe further fastened to the bar lOby providing-pins 19; that extend transversely of the fingers 16;beneaththe projections18 as will beappa rent fromFig. 2; the construction being such that the blocks are prevented by the pins 19 from being accidentally disengaged from the bar 10. Since the present grate bars are not subj ected to a rocking movement, as is customary in most stolrer mechanismathe grate blocks are easier to retain in place thanthe rocking grate blocks or caps, andas a result a pair of fingers 16, disposed in the transverse central plane ofthe block 11 will serve'to retain the block in place uponthe bar 10, while'this construction permits the opposite end portions oft-he block to expand freely lengthwise of the bar from the central securing means. Themaj or portion of the bar 10, it

will be noted, is relatively narrow in crosssection. This construction is desirable to permit a free passage of air upwardly through the hollow blocks 11 at each side of the supporting bar. v

As above indicated the bars lOarepreferably mounted for sliding movement towards and'f-rom the fuel bed and to this end thebars 10 are provided at their opposite ends with the downwardly extending projections 20 adapted to guide the bars in their sliding movement. The transversely extending bars 10 are supported at their opposite ends-upon the longitudinally extending beamsQl which aremore fully shown and described in my application above mentioned, andto the op-' posite faces of the supportingbeams 21 are securedthe spaced.blocksor angle irons 22 between which are provided slideways adapt ed to receive the projections 20. The .lower ends of the'projections 2O normally rest upon the lugs 23 formed upon the supporting beams, and the construction is such that the fuel engaging grate blocks 11 are held by the construction just described at a substantial distance above the beams 21, thus relieving these beams from the intense heat ofthe fuel bed. 1 The composite grate or stoker bars 7 may be raised and lowered to manipulate the "arranged to cooperate with adjacent blocks fuel bed by links 24 the upper ends-of which are connected to lugs 25 providedupon ,the .bars 10, and the lower ends 'of these links, may be connected to. rockingibars 26, but

since the mechanism for-raising and lowering the grate, bars forms no part of thejpresg;

cnt invention and is fully shown anddescribed. in said appllcatlon, a further d1sclosure of the same herein is believed'to be unnecessary. v x v The opposite ends of the grate blocks 11 are preferably provided with the grooves 27 to form the air passages 28 between a pair or blocks, and the depth of theside M11912- of the blocks is preferably such that the side walls of adjacent blocks will overlap each P other even when a rate bar is raised to its maximum position of elevation as. shown at the right-hand side ofFig. 1 of the drawings. In other words, each side wallhl2 of a block extends downwardly below the upper edge of thesupportingloar 10 and forms an'apro'n that lies in spaced relation to the bar throughout the length of-theblock, thus in creasing the radiating surface; e Y I i This constructionprevents"a largeopening' from occurring between adjacent stoker bars when one is raised while the other sm its-normal or lowered position, and also prevents cllnlrers from lodglng between ad acent bars to interfere with their sliding movement. The

hollow grate blocks 11 herein described are s free from projecting lugs ,or fingers which are forced upwardly into the fuel bed to be burnt off by the high temperature of the fuel, and theentire structure is such that the 'composite grate or stolrer bars formed in a,c-' cordance with the present invention will withstand thehigh temperature of a furnace glmmnugh better than the stoker bars employed heretofore.

What is cla1med-1s:

1. In a furnace grate, in combination, a

grate bar, an approximately cubical grate block mounted on said bar in straddling relation therewith and provided-with. a fiat upper face and deep side and end walls that form well defined air passages leading upextend downwardly'froln the upper face of the block a distance nearlyequal to the length of the block to provide heat radiating walls, the lower ends ofsaid side wallsbeing-disposed in spaced relation to the grate bar to wardly into the block at each side of saidbar, said side walls being disposed in substantially parallelrelation to each other and provid V 7 ed with flat smooth outer surfaces, and partitions extending transversely of the block in spaced relation to eachother to-formlong'- vertical air passages, extending upwardly through the block.

2. In a furnace grate, in combination, ,a

grate bar. provided with substantially paral i 'lel side faces, a 'series of grate blocks mountfled on saidbar in'straddling relationtherewith and each comprising a substantially cubial hollow block provided with aflat upper face and vdeep end walls and deep flat flat and practically parallel and constructed lso extend downwardly a pronounced distance i from the upper face of the-block into the cooler zone beneath the fuel bed and disposed in spacedrelationto said side faces of the] grate bar to form well defined airpass'ages side walls, said side walls being smooth and leading upwardly into the blockat each side I of saidbar, and partitions extending between the side walls of the block to provide vertig cal air passages'extending upwardly through" the block from a position well below the fuel bed. 3. Ina furnace grate, combination, a

grate barp-rovidedwith approximately parallelside f ces, a hollow substantial cubical p a. 1 ae a l km unt-eden the, bar in straddlin relation therewith and provided with block 'positioning surfaces adaptedto-engage the {side faces of the bar, said block beingpro vided with end walls and deep substantially parallel 'side walls, the side walls being "smooth and flat 'and constructed to extend downwardly below the upper face of the grate bar inspace'drelation to its side "faces to" form welljdefined air passagesdeading, 5 .v

b'ar,-an dpartitions formedbetween the walls: T

upwardly into the block at'each side of said of the'l'bloclr to provideairpassages extending upwardly through the block so that air enters the interior of the block frompoints, a

well below the upper edge of the grate bar.

4]In a furnace grate, in combination, a

grate bar, a hollow approximately cubical grate block mounted on the bar and provided I with notched end walls extending down wardly into straddling relation with the 'cenj trally' disposed bar, said blockrbeingfpro f vided with smooth and'flat'side wallsthat'are substantially parallel and constructed to extions formed between the walls of the block to provide air passages leading upwardly point below the through thelblock from a upper. edge of the grate bar. In testimony whereof, I name to this specification.

GEORGE H. TEACHER, Ja ay have signed my] i 

